Panic Room
by HolyCowsAndFlyingPigs
Summary: He was lucky, really, Sam reflected, that Bobby's old safe room had been built underground and entirely out of metal. Lucky that while Bobby's house had been destroyed, the basement had stayed pretty much intact, even after all these years. Yeah, he was probably the luckiest guy in the world. Set post-season 9 finale. Features a kinda scary demonic Dean Winchester.


_A/N: So I'm not sure where this came from. It's... well, it's darker than I thought it would be. But I'm happy with it. Leave me a review if it suits your fancy, I'd love to know what you think!_

_Anyway, I don't own Supernatural, and sadly, I'm not making any money from this. _

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How had they come to this?

Sam pressed his palms against his ears and squeezed his eyes shut, trying to shut out the pounding and the swearing and the threats. He reminded himself that this wasn't Dean, not _his _Dean. This wasn't the brother who had raised him and protected him against things that went _bump_ in the night. It had to be Cain, or, arguably, just his Mark.

Sam never met Cain, but he thought he knew how Abel must have felt.

He was lucky, really, Sam reflected, that Bobby's old safe room had been built underground and entirely out of metal. Lucky that while Bobby's house had been destroyed, the basement stayed pretty much intact, even after all these years.

Yeah, he was probably the luckiest guy in the world.

He could have laughed at the irony. Sam hated this room. He'd run out of fingers to count the number of times Dean had locked him in here for his safety or for Sam's: it didn't really matter in the long run. Now Dean had done it again... in a sense. Sam traced a circle in the thick film of dust on the floor. The banging stopped. A metallic creaking told him Dean was trying to pull the door off its hinges. It wouldn't work. Sam made the angel seal him in before he left. Castiel hadn't wanted to, but Sam could be very convincing. Besides, Dean needed to be distracted while Cas researched how to save a demon soul.

And if there was one thing you could count on these days, it was his demonic obsession with killing his younger brother.

Sam added a star to the center of the circle, completing the pentagram. The creaking stopped and Dean started to laugh.

"Come on out, Sammy," Dean called from outside. "I'll make it quick, two days tops. Scout's honor."

Sam started on a Buddhist symbol of peace and protection. "I'll pass, thanks."

It had taken a couple days to adjust to the knowledge that the demon wasn't _in _Dean, but _was _Dean. When Sam first found out, he convinced himself that Dean was still Dean and that's all that mattered. The Winchesters could do anything, as long as they did it together. Apocalypse? Piece of cake. Ancient evil? Walk in the park. Knight of Hell? Too easy. Demon brother? Bring it on.

That was before the blood lust. Sam knew the Mark had affected his brother, he always maintained some control over it. After he died, whatever control he had was buried six feet deep, leaving the demon to do his worse. Dean started bringing home gifts like a cat proudly dropping a dead animal on its owner's porch. A vampire head here, a werewolf heart there. The entrails of a wendigo strung up like streamers to cheer up the place.

Sam started locking his door at night after that _gift_.

"Sammy," Dean crooned in the present. "You can't stay in there forever you know. You gotta eat and drink and sleep. I don't."

Sam patted the backpack next to him to reassure himself. He had enough food to last a week if he rationed it. And water enough for two. The old mattress was a little mildewy, but Sam didn't mind all that much. He drew a spiraling Enochian glyph that Cas had taught him. Apparently it was a complete translation of the Book of Revelations.

Sam's faith in his brother finally broke the day he brought back a human. Sam didn't know her, and Dean most likely had picked her up at some bar. She was alive when she arrived at the bunker, at least. Sam wasn't sure what happened exactly, only that one moment she was screaming and the next she wasn't. He had rushed from a dusty filing room to find the blonde bombshell lying in a pool of her own blood. Dean dipped his fingers in the dark puddle, looking painfully bored and uninterested.

Dean then told him how he was tired of playing nice. The Mark _burned_ every time Dean so much as looked at Sam. But it hummed pleasantly each time he killed.

It nearly sang, Dean told him casually, when he thought about killing his kid brother. He said he wondered what the real thing would feel like.

Such was Cain's curse.

"You're going to make me wait, aren't you?" Dean pounded on the door twice. "But that's just like you, isn't it, Sammy? Doing things the hard way is kinda your style." There was a pause, like he was waiting for Sam to reply. "That's alright, Sammy. Even if I can't get in, you can't get out. You're waiting for the angel to show up and save your ass. Don't worry, Sammy. I'll kill him too."

Sam let out a shuddering breath, letting tears silently roll down his cheeks. He made sure to be quiet so his brother wouldn't hear. _That's alright, Sammy. Don't worry, Sammy_. The familiar phrases lent him no comfort now.

_If that's Cain's curse then this must be Abel's,_ Sam observed humorlessly. He was getting sick of fate or destiny or God or whoever messing around with him. It was like someone out there, playing a twisted cosmic game, wanted one of the brothers to kill the other.

Sam ran the night Dean killed the nameless blonde, visions of biblical brothers beating each other with animal bones urging him faster. He took the Impala, partially because she was the only home he'd ever known, but also because the thought of his demon brother touching her with his blood-stained hands made him physically ill. So it went, for months it seemed. Sam fled, Dean chased. Castiel appeared at some point, looking defeated and weak, but still loyal to a T.

All of that had led them here, Bobby's panic room. The long stall they needed before they could save Dean Winchester. _If_ they could save him, that is.

Dean started singing a Metallica song that Sam had never liked. As a kid, it gave him nightmares anytime he heard it before going to sleep in the backseat on a particularly long drive. The sound of wings momentarily drowned out the muffled tune.

"The third trial," Cas fell heavily against a wall. "It's the only way to cure a demon." The angel looked ready to collapse from exhaustion.

"You've looked everywhere?" Sam asked softly, not at all surprised. He figured it would come down to this. Oddly poetic, wasn't it? To save his brother's demon soul, he had to close the gates of Hell. That was just the kind of romantic bull that seemed to lurk around every corner of his life. Castiel nodded and slid down the wall into a limp heap.

"Cas, I've already completed the first two trials," Sam said meaningfully. Cas' body gently shook with the effort it took to stay conscious.

"I know."

Dean stopped humming long enough to say, "You got Cas in there too? That's not fair, Sammy, you're playing with my favorite toy." He banged against the door. "Open up, angel, I know you don't have much longer. I can _f__eel_ the Grace burning you alive."

Sam took a deep breath. "What are the chances I'll survive?" He knew the answer already.

"You won't," the angel's reply was barely audible. Figures, Sam thought, it's always choosing between a rock and a hard place.

So it came down to a deal, just like old times: his life for Dean's.

The choice was simple when he put it like that.


End file.
